Up to 45 percent of employees feel obligated to check-in after business hours, and another 26 percent feel guilty for using their vacation time.

A new employee engagement study by Ranstad looked at work/life balance perceptions among U.S. workers and found that technology is blurring the lines.

About 120 million U.S. workers are now classified as mobile workers (those who work from their mobile devices). And according to the longitudinal study of 2,257 adult employees, Gen Y lives in “default mode.”

American workers are beginning to resent the encroachment of technology into their personal lives; employees fear retribution for being unavailable or failing to check-in on a constant basis when off the clock.

Up to 45 percent of employees feel obligated to check-in after business hours or while on vacation, and another 26 percent feel guilty for using their vacation time, not working from home or if they’re sick.

While many American companies are becoming more flexible in their approach to the work/life balance, clear policies are still needed to curtail fear and burnout, and ensure employees’ down time is respected.

Europeans appear to be protecting their workers’ down time with greater proclivity. A report by Germany’s Federal Institute for Occupational Safety and Health (BAuA) found that “as work encroaches on people’s private lives, the more employees are likely to suffer from stress, burnout and an inability to switch off.”

In 2011, Volkswagen agreed to stop its Blackberry servers from sending emails to some of its employees when they are off-shift.

Last Christmas, Mercedes-Benz launched an “absence assistant” to delete emails arriving in employees’ inboxes while they are on vacation. BMW lets the time spent on work emails offsite or outside of work hours count as overtime.

This year, in accordance with the country’s 35-hour workweek, more than 300,000 tech-sector employees in France were guaranteed the right to unplug after work and not respond to emails.

Sweden is also considering a 35-hour workweek unencumbered by technology.

U.S. workers can protect themselves by being proactive:

Ask about work/life balance protections and policies during interviews.

Set clear boundaries with clients and colleagues (and be sure to follow them yourself).